TypeError: unhashable type: 'Pmf' (thinkbayes.py)

[ssrrapper]

When trying to run code from hockey.py, I get:

Traceback (most recent call last):

File "", line 1, in
runfile('C:/Users/ssrra/.spyder-py3/temp.py', wdir='C:/Users/ssrra/.spyder-py3')

File "C:\Users\ssrra\AppData\Local\Continuum\anaconda3\lib\site-packages\spyder_kernels\customize\spydercustomize.py", line 827, in runfile
execfile(filename, namespace)

File "C:\Users\ssrra\AppData\Local\Continuum\anaconda3\lib\site-packages\spyder_kernels\customize\spydercustomize.py", line 110, in execfile
exec(compile(f.read(), filename, 'exec'), namespace)

File "C:/Users/ssrra/.spyder-py3/temp.py", line 541, in
main()

File "C:/Users/ssrra/.spyder-py3/temp.py", line 435, in main
goal_dist1 = MakeGoalPmf(suite1)

File "C:/Users/ssrra/.spyder-py3/temp.py", line 127, in MakeGoalPmf
metapmf.Set(pmf, prob)

File "C:\Users\ssrra.spyder-py3\thinkbayes.py", line 589, in Set
self.d[x] = y

TypeError: unhashable type: 'Pmf'

[AllenDowney]

I will check it out. Thanks for letting me know.